title: Dynamics of physical interaction between HIV-1 Nef and ASK1: identifying the interacting motif(s).
abstract: FasL mediated preferential apoptosis of bystander CTLs while protection of infected CD4(+)T cells remains one of the hallmarks of immune evasion during HIV infection. The property of infected host cells to evade cell-autonomous apoptosis emanates from ability of HIV-1Nef-protein to physically interact with ASK-1 and thereby inhibit its enzymatic activity. The specific domains of HIV-1Nef through which it may interact with ASK1 and thereby impair the ASK1 activity remain unidentified so far and represent a major challenge towards developing clear understanding about the dynamics of this interaction. Using mammalian two hybrid screen in association with site directed mutagenesis and competitive inhibitor peptides, we identified constituent minimal essential domain (152 DEVGEANN 159) through which HIV-1Nef interacts with ASK1 and inhibits its function. Furthermore our study also unravels a novel alternate mechanism underlying HIV-1 Nef mediated ASK1 functional modulation, wherein by potentiating the inhibitory ser(967) phosphorylation of ASK1, HIV-1Nef negatively modulated ASK1 function.
authors.affiliation: Division of Toxicology, Central Drug Research Institute (Council of Scientific & Industrial Research), BS-10/1, Sector-10 Jankipuram Extension, Uttar Pradesh, India.
authors.forename: Balawant
authors.initials: B
authors.lastname: Kumar
authors.forename: Chakrapani
authors.initials: C
authors.lastname: Tripathi
authors.forename: Ranjana K
authors.initials: RK
authors.lastname: Kanchan
authors.forename: Jitendra Kumar
authors.initials: JK
authors.lastname: Tripathi
authors.forename: Jimut K
authors.initials: JK
authors.lastname: Ghosh
authors.forename: Ravishankar
authors.initials: R
authors.lastname: Ramachandran
authors.forename: Smrati
authors.initials: S
authors.lastname: Bhadauria
authors.forename: Raj Kamal
authors.initials: RK
authors.lastname: Tripathi
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis; D001665:Binding Sites; D001667:Binding, Competitive; D057809:HEK293 Cells; D015497:HIV-1 / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D019169:Jurkat Cells; D048848:MAP Kinase Kinase Kinase 5 / Q000737:chemistry* / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D020798:Two-Hybrid System Techniques; D054311:nef Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D054311:nef Gene Products, Human Immunodeficiency Virus; C514837:nef protein, Human immunodeficiency virus 1; D048848:MAP Kinase Kinase Kinase 5; C482858:MAP3K5 protein, human